JP6537610B2 - Apparatus and method for inspecting ceramic honeycomb body - Google Patents

Description

priority

  This application claims the benefit of priority to US Provisional Patent Application No. 62 / 084,355, filed Nov. 25, 2014, the contents of said provisional patent application being credible, the entire content of which is incorporated by reference. Are incorporated into the present application.

  Exemplary embodiments of the present disclosure relate to an apparatus and method for manufacturing a ceramic honeycomb body, and more particularly to an apparatus and method for automatically inspecting the ceramic honeycomb body in manufacturing a ceramic honeycomb body.

  Post-treatment of exhaust gases from internal combustion engines using a catalyst supported on a high surface area substrate and a catalytic filter for removal of carbon soot particles in the case of diesel engines and some gasoline direct injection engines There is. Porous ceramic flow-through honeycomb substrates, and wall flow honeycomb filters may be used in these applications.

  The above information disclosed in the above "Background Art" section is only to enhance the understanding of the background of the present disclosure, and therefore, the above information may be any part of the prior art that the prior art may suggest to one skilled in the art. It may include information that is not formed.

  Exemplary embodiments of the present disclosure provide an inspection apparatus for inspecting a ceramic honeycomb body automatically.

  The exemplary embodiments of the present disclosure also provide a method of automatically inspecting a ceramic honeycomb body.

  Further features of the present disclosure are described in the following "Forms for Carrying Out the Invention", and are partially apparent from the "Forms for Carrying Out the Invention" or can be learned by the practice of the present disclosure.

  One exemplary embodiment discloses an inspection apparatus for inspecting a ceramic honeycomb body automatically. The apparatus comprises: a light source configured to emit light towards a first end of the ceramic honeycomb body; configured to receive at least a portion of the light transmitted through a channel of the ceramic honeycomb body. A lens; an imaging device configured to capture an image of the transmitted light; a support chuck configured to support the honeycomb body; and each of the captured images receiving the captured image And adjusting the support chuck based on the analysis, and a controller configured to align the channel and lens optic axes based on the analysis.

  Certain exemplary embodiments also disclose an apparatus for producing a ceramic honeycomb body. The apparatus comprises an inspection apparatus, the inspection apparatus comprising: a light source configured to emit light towards a first end of the ceramic honeycomb body; the light transmitted through a channel of the ceramic honeycomb body A lens configured to receive at least a portion of the light; an imaging device configured to capture the transmitted image of the light; a support chuck configured to support the honeycomb body; and the captured image And a controller configured to analyze each of the captured images, adjust the support chuck based on the analysis, and align the channel and lens optic axes based on the analysis.

  Certain exemplary embodiments also disclose a method of automatically inspecting a ceramic honeycomb body. The method comprises: emitting light towards a first end of the ceramic honeycomb body, wherein at least a portion of the light is transmitted through a channel of the ceramic honeycomb body; through a lens Imaging the portion of the light; imaging a plurality of images at incremental angles between the channel and the optical axis of the lens; analyzing at least a portion of the imaged image; Adjusting the ceramic honeycomb body based on the analyzing step to align the channel and lens optic axes.

  Certain exemplary embodiments also disclose a method of manufacturing a ceramic honeycomb body. The method comprises the steps of automatically inspecting the ceramic honeycomb body, the inspecting step: emitting light towards a first end of the ceramic honeycomb body, the method comprising the steps of: Imaging a portion of the light through the lens, a portion being transmitted through a channel of the ceramic honeycomb body; a plurality of images at incremental angles between the channel and an optical axis of the lens; Imaging at least a portion of the imaged image; and adjusting the ceramic honeycomb body based on the analyzing to align the optical axis of the channel and the lens.

  It is to be understood that both the foregoing Summary of the Invention and the following Detailed Description of the Invention are exemplary and explanatory and are intended to provide a further description of the present disclosure. I want you to understand.

  The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated into and constitute a part of the specification, which are the principles of the disclosure. Fig. 3 illustrates an exemplary embodiment of the present disclosure, along with a description that serves to illustrate the

1 is a schematic side view of an inspection apparatus according to an exemplary embodiment of the present disclosure Schematic of light from a scattered light source partially blocked by the walls of the ceramic honeycomb body of the inspection device according to an exemplary embodiment of the present disclosure Schematic top view of an inspection apparatus according to an exemplary embodiment of the present disclosure Schematic of an inspection apparatus according to an exemplary embodiment of the present disclosure An end view of a portion of the support chuck of the inspection apparatus looking towards a scattered light source according to an exemplary embodiment of the present disclosure Schematic flow chart of an exemplary method for aligning a yaw of a ceramic honeycomb body in an inspection apparatus according to an exemplary embodiment of the present disclosure Schematic flow chart of a method for calculating average light intensity in an exemplary method of aligning ceramic honeycomb bodies in an inspection apparatus according to an exemplary embodiment of the present disclosure Schematic flow chart of an exemplary method for aligning the pitch of ceramic honeycomb bodies in an inspection apparatus according to an exemplary embodiment of the present disclosure An end view of a portion having defects in a support chuck of an inspection apparatus, as viewed toward a scattered light source, according to an exemplary embodiment of the present disclosure An end view of the portion having the defect shown in FIG. 7A after yaw rotation, according to an exemplary embodiment of the present disclosure

  The porous ceramic honeycomb body is produced by plasticizing a ceramic powder batch mixture, extruding the mixture through a honeycomb extrusion die to form a honeycomb extrusion, cutting, drying and firing the honeycomb extrusion, This can be achieved by the process of manufacturing a high strength and high temperature resistant ceramic honeycomb body having a channel extending axially from one end face to the second end face. As used herein, ceramic honeycomb bodies include ceramic honeycomb monoliths and ceramic segmented honeycomb bodies.

  The coextruded or later applied skin may form the outer axial peripheral surface of the ceramic honeycomb body. Regardless of whether the honeycomb body is monolith or segmented, a filter can be manufactured by blocking each channel of the honeycomb body at the inlet or outlet face. If some channels are left unblocked, partial filters can be made. Regardless of whether the honeycomb body is monolith or segmented, the honeycomb body can be catalyzed to produce a substrate. Additionally, filters and subfilters can be catalyzed to create multifunctionality. The ceramic honeycomb body produced in this manner is widely used as a ceramic catalyst support for automobile exhaust systems, and as a catalyst support and wall flow particle filter for removing soot and other particles from engine exhaust. Ru.

  Among the processes leading to good commercial results for ceramic honeycomb manufacture are those that utilize large co-rotating twin screw extruders for mixing and extrusion of ceramic honeycomb extrudates. Ram extrusion, pressing, casting, spraying and three-dimensional printing are other processes for ceramic honeycomb body production.

  Exemplary embodiments of the present disclosure provide an apparatus for automatically inspecting a honeycomb body, and a method for automatically inspecting a ceramic honeycomb body. According to these exemplary embodiments, apparatus and methods are provided that automatically align the part with the inspection system optical axis to image the substrate for internal defects.

  Working with an automatic light box system has revealed that the light box method is less repeatable if the process does not have a reproducible alignment method. Experiments with manual lightbox inspection and in the laboratory have demonstrated that slight changes in the orientation of the part to be inspected change the appearance of internal defects. It has been found that automatically finding the orientation in space within the parallel channels of the part in a reproducible and accurate manner provides reproducible images for reproducible image analysis and defect detection.

  An extruded porous ceramic honeycomb body (referred to herein as a "part") having axially extending channels can be inspected automatically after firing according to an exemplary embodiment of the present disclosure. The disadvantages of the automatic inspection system overcome by the present disclosure include the automatic registration of the part to be inspected with the inspection device and appearance or disappearance or appearance depending on the alignment of the substrate to be inspected. Reproducible, automated methods for finding defects that may change. The present disclosure provides an apparatus and method of automatic optical inspection for internal defects that overcomes these difficulties.

  FIG. 1 is a schematic side view of an inspection apparatus 100 according to an exemplary embodiment of the present disclosure. As schematically shown in FIG. 1, the scattered light source 102 provides light 104 towards a first surface (eg, an inlet surface) of the ceramic honeycomb body (part) 106. The scattered light source 102 (light source) may be a light source transmitted through a diffuser, or the scattered light source 102 may optionally be a collimated light source 102. For example, the scattered light source 102 can be a light box having a light emitting surface area larger than the end surface area of the component 106, said end surface area intersecting the axial direction of the component 106, a cross section through the component 106 It is. Light 108 transmitted through the component's channel is emitted from the second surface (eg, the exit surface) of component 106 towards telecentric lens 110. Telecentric lens 110 may optionally be Fresnel lens 110. A telecentric lens 110 (lens) images light passing through the area (diameter) of the part. For example, the lens 110 images an area larger than the end surface area of the part 106, said end surface area being a cross section through the part 106 intersecting the axial direction of the part 106.

  The camera 112 that receives the image from the lens 110 contains a detector that collects the image. The support chuck 114 provides support for the part 106 at the vertical reference angle 116. The vertical reference angle 116 is the angle between the outer peripheral axial surface of the part 106 and the reference axis, which extends along the optical axis of the lens from the light source 102 to the camera 112, for example from the light source 102 to the camera 112. It may be. The vertical reference angle 116 viewed from the side as in FIG. 1 may be referred to herein as a pitch angle. The acquired images may be communicated from camera 112 to controller 118 for analysis.

  FIG. 2 is a schematic view of light 104 from a light source 102 partially blocked at any angle by the channel walls 120 of the ceramic honeycomb body in an inspection apparatus 100 according to an exemplary embodiment of the present disclosure. Although the channel walls 120 are generally parallel to the outer peripheral axial surface of the part 106, they need not be like the relationship of the reference angle 116 with respect to the reference. As shown in FIG. 2, a portion of the light 108 is transmitted through the channels of the honeycomb body. As can be seen, when the honeycomb body channel is aligned with the light 104 from the light source 102, the channel wall 120 blocks less light 104 and more of the light 108 is transmitted.

  FIG. 3 shows a schematic top view of an inspection apparatus 100 according to an exemplary embodiment of the present disclosure. As shown schematically in FIG. 3, support chuck 114 provides support for part 106 at horizontal reference angle 122. The horizontal reference angle 122 is the angle between the outer peripheral axial surface of the part 106 and the reference axis, which extends along the optical axis of the lens 110 from the light source 102 to the camera 112, for example from the camera 112 to the light source 102. It may be. The horizontal reference angle 122 viewed from the top as in FIG. 3 may be referred to herein as the yaw angle.

  FIG. 4 shows a schematic view of an inspection apparatus 100 according to an exemplary embodiment of the present disclosure. FIG. 4 may be a side or top view after an alignment process, such as the mean of the channels 120 being aligned with the optical axis of the lens 110. Thus, the transport device, such as a conveyor, support or robot arm, can position the component 106 on the support chuck 114, for example at an angle to alignment with the lens optical axis having a pitch angle 116 and / or a yaw angle 122, The inspection apparatus 100 can also automatically align the channel 120 with the lens optical axis.

  FIG. 5 shows an exit end view of the part 106 in the support chuck 114 of the inspection apparatus 100 looking towards the light source 102 according to an exemplary embodiment of the present disclosure. FIG. 5 shows that the channel walls 120 need not be perfectly parallel to one another. A bright portion 510 traversing the center of part 106 from the top right to the bottom left of the figure shows light 108 transmitted through the channel. On the other hand, the dark portion 520 at the top of the figure and the dark portion 530 at the bottom of the figure indicate that the light 104 is blocked by the channel wall 120.

  FIG. 6A is a schematic flow chart of an exemplary method 600 for aligning the yaw of the ceramic honeycomb body 106 in the inspection apparatus 100 according to an exemplary embodiment of the present disclosure. Referring again to FIGS. 1, 3 and 4, inspection apparatus 100 can align the yaw of ceramic honeycomb body 106 by implementing the exemplary embodiment of method 600 of the present disclosure. In operation 602, the part 106 is placed in the apparatus 100, for example on the support chuck 114, and the horizontal reference angle 122 is recorded, for example by the controller 118. At operation 604, the controller 118 calculates an average intensity of the transmitted light 108.

  In operation 606, the controller 118 controls the support chuck 114 to tilt the part by an angular increment, for example, by + 0.1 ° of the yaw. The average intensity of the transmitted light 108 at this new yaw position is calculated by the controller 118 at operation 608. The controller 118, at operation 610, compares the average intensity of the transmitted light 108 at the new yaw position to the stored value of the average intensity of the transmitted light 108 at the previous yaw position. If the average intensity of the transmitted light 108 at the new yaw position is greater than the stored value of the average intensity of the transmitted light 108 at the previous yaw position, operation 612 increments the yaw angle increment (+0. Tilt the part by 1 °).

  Operation 614 recalculates the average intensity of the transmitted light 108 at the new yaw position, and at operation 616 the controller 118 determines the average intensity of the transmitted light 108 at the new yaw position as the previous yaw. Compare with the stored value of the average intensity of the transmitted light 108 at the location. If the average intensity of the transmitted light 108 at the new yaw position is greater than the stored value of the average intensity of the transmitted light 108 at the previous yaw position calculated at operation 616, operation 612 is: Tilt the part by the yaw angle increment (+ 0.1 °). Repeat operations 614 and 616.

  If the average intensity of the transmitted light 108 at the new yaw position is less than the stored value of the average intensity of the transmitted light 108 at the previous yaw position calculated at operation 616, the operation 618 may, for example, Tilt the part back to the previous yaw position by the negative yaw angle increment (−0.1 °). The yaw position determined by operation 618 is determined to be the yaw reference angle 122 aligned with the reference axis, and the process 600 ends at 620.

  Referring back to operation 610, controller 118, in operation 610, stores the average intensity of transmitted light 108 at the new yaw position with the stored value of the average intensity of transmitted light 108 at the previous yaw position. If, by comparison, the average intensity of the transmitted light 108 at the new yaw position is less than the stored value of the average intensity of the transmitted light 108 at the previous yaw position, then operation 622 may, for example, be negative. Tilt the part back to the previous yaw position by an angular increment (-0.1 °). Operation 624 calculates the average intensity of the transmitted light 108 at the new yaw position, and at operation 626, the controller 118 controls the average intensity of the transmitted light 108 at the new yaw position at the previous yaw position. The stored intensity of the transmitted light 108 is compared to the stored value.

  If the average intensity of the transmitted light 108 at the new yaw position is greater than the stored value of the average intensity of the transmitted light 108 at the previous yaw position calculated at operation 626, operation 622 Tilt the part by the above negative yaw angle increment (-0.1 °). Repeat operations 624 and 626. If the average intensity of the transmitted light 108 at the new yaw position is less than the stored value of the average intensity of the transmitted light 108 at the previous yaw position calculated at operation 626, the operation 628 may, for example, Tilt the part back to the previous yaw position by the yaw angle increment (+ 0.1 °). The yaw position determined by operation 628 is determined to be the yaw reference angle 122 aligned with the reference axis, and the process 600 ends at 630.

  FIG. 6A shows the hill climb method of determining yaw alignment. Other methods for determining yaw alignment include, for example, the downhill method or the amoeba method.

  FIG. 6B is a schematic flow chart of a method 632 of calculating average light intensity in an exemplary alignment method 600 for aligning the yaw of the ceramic honeycomb body 106 according to an exemplary embodiment of the present disclosure. Process 632 begins at operation 634 where an image of part 106 is captured, for example by camera 112. An example of a captured image is shown in FIG. 5, according to an exemplary embodiment of the present disclosure, an exit end view of the component 106 in the support chuck 114 of the inspection apparatus 100 looking towards the scattered light source 102. It is being imaged. In the yaw alignment process 600, at operations 604, 608, 614, and 624, a process 632 for calculating an average light intensity can be performed. In operation 638 of method 632 for calculating average light intensity, a region of interest (ROI) is extracted from the image, for example by controller 118. At operation 640, controller 118 calculates and returns the average pixel intensity of the ROI. Process 632 ends at operation 642.

  FIG. 6C is a schematic flow chart of an exemplary method 644 for aligning the pitch of the ceramic honeycomb body 106 in the inspection apparatus 100 according to an exemplary embodiment of the present disclosure. In operation 646, the part 106 is placed in the apparatus 100, for example on the support chuck 114, and the vertical reference angle 116 is recorded, for example by the controller 118. At operation 648, controller 118 calculates an average intensity of transmitted light 108. The method 632 for calculating average light intensity, illustrated in FIG. 6B and described above, may be used in this exemplary alignment method 644 according to an exemplary embodiment of the present disclosure.

  In operation 650, controller 118 controls support chuck 114 to tilt the part by an angular increment, for example, a pitch of + 0.1 °. The average intensity of the transmitted light 108 at this new pitch position is calculated by the controller 118 at operation 652. The controller 118 compares the average intensity of the transmitted light 108 at the new pitch position to the stored value of the average intensity of the transmitted light 108 at the previous pitch position at operation 654. If the average intensity of the transmitted light 108 at the new pitch position is greater than the stored value of the average intensity of the transmitted light 108 at the previous pitch position, operation 656 increments the pitch angle increment (+0. Tilt the part by 1 °).

  Operation 658 recalculates the average intensity of the transmitted light 108 at the new pitch position, and in operation 660 the controller 118 determines the average intensity of the transmitted light 108 at the new pitch position as the previous pitch Compare with the stored value of the average intensity of the transmitted light 108 at the location. If the average intensity of the transmitted light 108 at the new pitch position is greater than the stored value of the average intensity of the transmitted light 108 at the previous pitch position calculated at operation 660, operation 656 is: Tilt the part by a pitch angle increment (+ 0.1 °). Repeat operations 658 and 660.

  If the average intensity of the transmitted light 108 at the new pitch position is less than the stored value of the average intensity of the transmitted light 108 at the previous pitch position calculated at operation 660, operation 662 may, for example, Tilt the part back to the previous pitch position by the negative pitch angle increment (−0.1 °). The pitch position determined by operation 662 is determined to be pitch reference angle 116 aligned with the reference axis, and the process ends at 664.

  Referring again to operation 654, at operation 654, controller 118 determines the average intensity of transmitted light 108 at the new pitch position as the stored value of the average intensity of transmitted light 108 at the previous pitch position. If, by comparison, the average intensity of the transmitted light 108 at the new pitch position is less than the stored value of the average intensity of the transmitted light 108 at the previous pitch position, operation 668 may, for example, be negative. Tilt the part back to the previous pitch position by an angular increment (-0.1 °). Operation 670 calculates the average intensity of the transmitted light 108 at the new pitch position, and in operation 672 the controller 118 controls the average intensity of the transmitted light 108 at the new pitch position at the previous pitch position. The stored intensity of the transmitted light 108 is compared to the stored value.

  If the average intensity of the transmitted light 108 at the new pitch position is greater than the stored value of the average intensity of the transmitted light 108 at the previous pitch position calculated at operation 672, operation 668 returns Incline the part by the above negative pitch angle increment (-0.1 °). Repeat operations 670 and 672. If the average intensity of the transmitted light 108 at the new pitch position is less than the stored value of the average intensity of the transmitted light 108 at the previous pitch position calculated at operation 672, operation 674 may, for example, Tilt the part back to the previous pitch position by the pitch angle increment (+ 0.1 °). The pitch position determined by operation 674 is determined to be pitch reference angle 116 aligned with the reference axis, and the process ends at 676.

  FIG. 6C shows the hill climb method of determining pitch alignment. Other methods for determining pitch alignment include, for example, the downhill method or the amoeba method.

  The schematic flow chart of method 632 for calculating average light intensity of FIG. 6B is used in an exemplary alignment method 644 for aligning the pitch of ceramic honeycomb body 106 according to an exemplary embodiment of the present disclosure it can. In the pitch alignment process 644, processes 632 for calculating the average light intensity can be performed at operations 648, 652, 652, and 670.

  Although yaw and pitch alignment have been described with respect to movement of the position of part 106, the present disclosure is not so limited. According to an exemplary embodiment of the present disclosure, the angular position of the lens 110 can also be controlled while the part 106 is stationary. Control of the position of the component 106 to be imaged to control the position of the component 106 with the optical axis of the lens 110 by controlling the position of the lens 110 by the following method similar to that described above with reference to FIGS. 6A, 6B and 6C It can produce the same effect as aligning. In such an embodiment, the lens can be moved in the pitch and yaw directions by controlling it with the controller 118.

  Although pitch angle 116 and yaw angle 122 have been described with respect to side and top views, respectively, pitch angle 116 and yaw angle 122 can be in any orientation. In general, the pitch angle 116 and the yaw angle 122 are orthogonal to one another. Although the terms top, bottom, side, upper, lower, vertical and horizontal are used, the disclosure relates It is not limited to these exemplary embodiments. Instead, relative terms relating to space, such as top, bottom, horizontal, vertical, side, beneath, below, below Lower, above, upper, etc., in the present application, for ease of explanation, one element or feature relative to another one or more elements or one or more features. , Can be used to illustrate the relationships as illustrated in the figures. It should be understood that relative terms relating to space are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted. For example, inverting the device in the figure will cause elements described as "below" or "directly below" other elements or features to be oriented "above" the other elements or features. Thus, this exemplary term "lower" can encompass both upper and lower orientations. The device may be at other orientations (it may be rotated at 90 ° or other orientations) and the relative descriptors for space used in the present application may be interpreted accordingly. Thus, when the inspection device of FIG. 1 is rotated 90 degrees, the exemplary term "side" can be "top" and vice versa.

  A position (pitch angle 116 and yaw angle 122) is established where component 106 is aligned with the imaging system (optical axis of lens 110), ie the average intensity of the uniformly illuminated image of component 106 is maximized This information may then be used to inspect the part for internal defects. The position (pitch angle 116 and yaw angle 122) of the part 106 aligned with the imaging system (optical axis of lens 110) is referred to herein as the alignment angle. This alignment angle is the optimal viewing angle for some defects. It is also the reference position that can be used to determine how to view other defects where this alignment angle is not the optimal viewing angle. The controller 118 can control the entire process, including imaging, analysis of the image to determine average intensity, motion required for the registration process, and imaging and analysis of the image for detection of defects.

  The ceramic honeycomb structure 106 may exhibit multiple types of internal defects that can be detected using the inspection apparatus 100 according to an exemplary embodiment of the present disclosure. Internal cracks that may occur during firing are areas in which the cell walls of many adjacent cells are broken. Internal tearing can be caused during extrusion by an area of uneven batch flow through the die, which is like a "honeycomb" inside of part 106 when viewed from the exit end towards light source 102. It looks like Expanded webs may also be caused during extrusion by areas of non-uniform batch flow through the die, which may appear as thick webs in the image from the camera 112 in the apparatus 100. The dead channel is a defect caused by the insufficient formation of the peripheral cells of the part 106, which leads to blocking of the peripheral cells during the peeling process. The present disclosure provides methods and apparatus for automated inspection of ceramic honeycomb structures for at least one of these defects (cracks, tears, expanded webs, occluded channels, etc.).

  For each of the different types of potential defects, defect specific inspection techniques may be employed. For example, an internal fracture may appear as a faint line across the surface of part 106 when imaged from an alignment angle with the apparatus 100 described herein. Displacing the alignment of the part from the alignment angle in a direction with some component perpendicular (90 °) to the line representing the break improves the contrast of the break in the image. The cracks begin to appear to cast shadows on the entire face of the part. This example can be confirmed in FIGS. 7A and 7B.

  FIG. 7A illustrates an exit end view of a portion 106 having defects 710 (cracks) in the support chuck 114 of the inspection apparatus 100 as viewed toward the scattered light source 102 according to an exemplary embodiment of the present disclosure. When rotating the part 106 so that the surface of the part 106 appears to move towards the right (changing the yaw angle), the shadow 720 disappears slowly and a shadow 730 reappears on the left side of the crack 710. FIG. 7B shows an end view of the portion 106 having the crack defect 710 shown in FIG. 7A after yaw rotation, according to an exemplary embodiment of the present disclosure.

  The shadow 730 may show an acute slope on the boundary in a direction that is known based on the direction in which the part 106 has moved from the alignment angle. When the part 106 is undergoing positive displacement along the yaw axis, the shadow 730 of the crack 710 exhibits a large negative slope in the image. When the part 106 is undergoing a negative displacement along the yaw axis from the alignment angle, the shadow 720 of the crack 710 exhibits a large positive slope. The controller 118 can process the image to check that one gradient is present and the other is not. The displacement angle can be canceled (part 106 moves in the opposite direction by the same distance from the alignment angle) and the controller can again check that one gradient is present and the other is not. This behavior is unique among the features found during imaging of cellular ceramic substrates. Thus, the inspection apparatus 100 can detect internal cracks with excellent repeatability and accuracy. This type of observation and detection is possible after initially determining the alignment angle with the inspection apparatus 100 according to these exemplary embodiments.

  With the inspection apparatus 100 according to these exemplary embodiments, other internal defects common in extruded cellular ceramic substrates can be detected as well. According to these exemplary embodiments, the devices and methods described herein can inspect the honeycomb body 106 repeatedly and automatically.

  Further, the determination of the alignment angle reference allows the inspection apparatus 100 to capture images at a plurality of angles with respect to the alignment angle to locally maximize the contrast of the image. This may be necessary when imaging the substrate 106 as shown in FIG. By illuminating the dark portions 520, 530 in the part 106 such as that shown in FIG. 5 by operating the support 114 with the controller 118 to effect a small angular displacement around the alignment angle. it can. That is, a first alignment angle can be established where the bright portion 510 is the maximized average brightness of the image of the part 106, ie, the entire surface of the part 106. However, a second alignment angle may also be established where the average lightness is maximized in the dark portion 520. In addition, a third alignment angle can be established where the average lightness is maximized in the dark portion 530. Portions 510, 520 and 530 may optionally be distributed from part to part. Thus, the surface of the part may be divided consistently into two or more sectors, and for each sector, when one sector is aligned at the alignment angle of the sector, all channels are in that sector. Alignment angles are established so that one average lightness is also within the maximized part.

  The sector alignment angle may be established in a manner similar to establishing the alignment angle from images captured at multiple angles with respect to the alignment angle. The part 106 can be imaged with a composite image of average brightness maximized in each sector, where each image in the composite image covers one sector of the end face of the part 106. For example, imaged component 106 may be imaged by 16 sectors, each sector having a maximized average brightness and a sector alignment angle associated therewith. In this example, the image is divided into 16 "pie slices". The inspection process may inspect each sector around alignment angles specific to each sector to detect defects. That is, the apparatus and process can examine all captured images to find which image produces the best contrast for each "pie slice". Next, the highest contrast pie slice is examined for internal defects such as cracks, internal tears, internal expanding webs or occlusion channels. The number of sectors is not particularly limited, and may be, for example, 2 to 64.

  The present disclosure is further described below with respect to specific exemplary and specific embodiments of the present disclosure. The above embodiments are merely illustrative and not intended to be limiting. According to some of the embodiments, the scattered light source 102, the telecentric lens 110, the camera 112 with the detector 112, the honeycomb support chuck 114 as described herein, for example, with reference to FIGS. And a prototype of the inspection apparatus 100 according to an exemplary embodiment of the present disclosure, comprising a controller 118. The inspection apparatus 100 was used for automated internal viewing of a solid substrate 106 and provided improved repeatability and accuracy as compared to manual inspection with a light box. As described in Table 1, “Kappa value in evaluator” is an indicator of the reproducibility of the device 100. The “rater vs. standard κ value” is an index of the match between the inspection apparatus 100 and the standard value determined by the quality standard. The above quality standard is established by the quality department. In essence, the "K value" is a recalibrated percent match with the criteria, eliminating the chance match. A higher κ value means that the inspection apparatus 100 according to an exemplary embodiment of the present disclosure more closely matches the reference value. In other words, the higher the "rater-to-reference κ value", the higher the accuracy of the inspection apparatus 100.

  Data were acquired by conducting experiments using the prototype apparatus 100. Twenty-eight parts 106 were characterized by the quality department as "pass" or "fail" (Ref). These parts 106 were subjected to an experiment on the inspection apparatus 100 for three repetitions (Rep). For each iteration, it was recorded whether the device 100 passed or failed the part 106 (P / F). Device 100 also identified the type of defect as a "reason" for the failure. This data is shown in Table 2. Statistical analysis was then used to calculate "Kappa value within evaluator" and "Kappa value of evaluator versus reference".

  False rejection (α risk): The data in Table 2 are two examples for which all the three Reps disagreed with Ref and returned to rejection for the part 106 deemed to be acceptable by Ref, 188 And 525. FIG. Two further examples had a single Rep, 227-3 and 507-2, respectively, which failed the part 106 that was deemed a pass by Ref.

  Mismatch of reasons: Although the two Reps (Rep 368-2 and 368-3) of the two Examples 381 and 505, and the third Example 368 were consistent with the Ref for the failed part 106, they were not The reason for the pass, internal cracking, continuous internal cracking, did not match the Ref.

  False Pass (β Risk): A further example 134 had one Rep, 134-2, which passed the part 106 that was deemed to be rejected by the Ref. Rep1 of Example 368 described above in "reasons disagreement" also passed if Ref considered part 106 as a failure.

  The advantages of the apparatus and method of inspecting honeycomb bodies provided by the present disclosure include economical automatic alignment and inspection of ceramic honeycomb structures. That is, alignment and inspection use the same hardware, which provides manufacturing cost savings and efficiency. Exemplary embodiments of the present disclosure provide reproducible images of defects for reproducible image analysis and defect detection. In order to obtain reproducible images, the exemplary embodiments of the present disclosure provide orientation in a reproducible and accurate manner within the space of parallel channels of a part. Exemplary embodiments of the present disclosure provide methods and apparatus for aligning a ceramic substrate with an optical axis of a machine vision inspection system in an accurate and repeatable manner. The exemplary embodiments of the present disclosure also provide improved alignment for large ceramic honeycomb structures. The apparatus and method of the present disclosure take into account the low parallelism of the channels in large parts and determine the optimal alignment with high repeatability. The use of telecentric or Fresnel lenses offers the advantage that a very large number of channels of ceramic substrate can be realized along the optical axis of the imaging system. This allows efficient and robust inspection of the more non-parallel channels of the substrate, which occur more frequently as the size of the substrate increases.

  An exemplary embodiment of the present disclosure for detecting internal defects in a ceramic substrate by imaging and analyzing a plurality of images as described herein is a single imaging technique and Improves accuracy and repeatability compared to other techniques such as manual inspection. Another advantage of the apparatus and method of inspecting a honeycomb body provided in accordance with the present disclosure is that the face of the honeycomb body does not have to be perpendicular to the channels to determine the alignment angle.

  For the purpose of the present disclosure, "at least one of X, Y and Z" means X only, Y only, Z only or two or more items. It should be understood that it can be interpreted as any combination of X, Y and Z (eg XYZ, XYY, YZ, ZZ).

  References to exemplary embodiments throughout the specification, and similar descriptions throughout the specification may, but do not necessarily, refer to the same embodiments. Furthermore, the described features, structures or characteristics of the subject matter described in the present application with reference to certain exemplary embodiments may be combined in any suitable manner in one or more exemplary embodiments. Can.

  It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the spirit or scope of the present disclosure. Thus, it is intended that the appended claims cover the modifications and variations of this disclosure as long as they fall within the scope of the appended claims and their equivalents.

  Hereinafter, preferred embodiments of the present invention will be described separately.

Embodiment 1
An inspection apparatus for inspecting a ceramic honeycomb body,
A light source configured to direct light into a channel of the ceramic honeycomb body;
A lens configured to receive at least a portion of the light transmitted through the channel of the ceramic honeycomb body;
An imaging device configured to capture an image of the light transmitted;
A support chuck configured to support the honeycomb body; and receiving the captured images, analyzing each of the captured images, and based on the analysis, at least one of the support chuck and the lens. A controller configured to: adjust and align the channel and lens optical axes.

Embodiment 2
The apparatus according to embodiment 1, wherein the light source comprises at least one of a scattered light source and a collimated light source.

Embodiment 3
The device of embodiment 1 or 2, wherein the lens comprises at least one of a telecentric lens and a Fresnel lens.

Embodiment 4
The controller detects at least one defect in the honeycomb body by adjusting at least one of the support chuck and the lens and performing alignment of the channel and the lens optical axis. The device according to any one of the aspects 1 to 3.

Embodiment 5
The apparatus according to any one of the preceding embodiments, wherein the at least one defect comprises at least one of an internal crack, an internal tear, an expanding web, and an occlusion channel.

Embodiment 6
The controller is configured to determine an average transmitted light intensity by analyzing each of the images and to align the channel and the lens optical axis when the average transmitted light intensity is maximized. The device according to any one of the aspects 1-5.

Embodiment 7
The apparatus according to any one of the preceding embodiments, wherein the imaging device comprises a camera comprising a detector for capturing the image of the transmitted light.

Embodiment 8
Further comprising a transport device configured to position the ceramic honeycomb body on the support chuck,
The apparatus according to any one of the preceding embodiments, wherein the channel and the lens optical axis are not aligned with respect to at least one of yaw angle and pitch angle.

Embodiment 9
The controller further performs sector alignment by analyzing each of the captured images, adjusting the support chuck based on the analysis, and aligning the plurality of sectors of the channel with the lens optical axis. Configured to
9. The apparatus as in any one of embodiments 1-8, wherein each said sector comprises at least one channel not parallel to another one of said plurality of sectors.

Embodiment 10
The apparatus according to any one of the preceding embodiments, wherein the number of sectors is 2 to 64.

Embodiment 11
The controller is configured to adjust at least one of the support chuck and the lens to detect at least one defect in the sector by tilting the channel around each sector alignment. The device according to any one of the preceding embodiments.

Embodiment 12
An apparatus for producing a ceramic honeycomb body,
The device comprises an inspection device,
The above inspection device is:
A light source configured to direct light into a channel of the ceramic honeycomb body;
A lens configured to receive at least a portion of the light transmitted through the channel of the ceramic honeycomb body;
An imaging device configured to capture an image of the light transmitted;
A support chuck configured to support the honeycomb body; and receiving the captured images, analyzing each of the captured images, and based on the analysis, at least one of the support chuck and the lens. A controller configured to: adjust and align the channel and lens optical axes.

Embodiment 13
A method of automatically inspecting a ceramic honeycomb body,
Directing light towards a first end of the ceramic honeycomb body, wherein at least a portion of the light is transmitted through a channel of the ceramic honeycomb body;
Imaging the portion of the light through a lens;
Imaging a plurality of images at incremental angles between the channel and the optical axis of the lens;
Analyzing at least a portion of the captured image; and adjusting at least one of the ceramic honeycomb body and the lens based on the analyzing to position the channel and lens optical axes relative to one another A method comprising: aligning to a registration angle.

Fourteenth Embodiment
14. The method according to embodiment 13, further comprising the step of detecting at least one defect in the honeycomb body by adjusting at least one of the channel and the lens optical axis around the alignment angle. .

Embodiment 15
The method according to embodiment 13 or 14, wherein the at least one defect comprises at least one of an internal crack, an internal tear, an expanding web, and an occlusion channel.

Sixteenth Embodiment
The method according to any one of the embodiments 13-15, further comprising the step of recording at least one of the ceramic honeycomb body identifier and the type of defect if a defect is detected.

Seventeenth Embodiment
The analyzing step includes the steps of analyzing each of the images to calculate an average transmitted light intensity and aligning the channel and the lens optical axis if the average transmitted light intensity is maximized. The method according to any one of the aspects 13-16.

Embodiment 18
The analyzing step includes analyzing an image of a sector of the ceramic honeycomb body,
The ceramic honeycomb body comprises a plurality of the sectors, wherein at least one of the channels is not parallel to a channel in at least one other of the sectors,
18. The method according to any one of the embodiments 13-17, wherein adjusting based on the analysis comprises aligning a plurality of sectors of the channel with the lens optical axis.

Embodiment 19
19. The method according to any one of the claims 13-18, further comprising adjusting at least one of the channel and the alignment of the lens optical axis around each sector alignment to detect at least one defect in the sector. The method according to any one of the preceding.

Embodiment 20
A method of producing a ceramic honeycomb body, comprising
The method includes the step of inspecting the ceramic honeycomb body,
The steps to check are:
Directing light towards a first end of the ceramic honeycomb body, wherein at least a portion of the light is transmitted through a channel of the ceramic honeycomb body;
Imaging the portion of the light through a lens; imaging a plurality of images at incremental angles between the channel and the optical axis of the lens;
Analyzing at least a portion of the captured image; and adjusting the ceramic honeycomb body based on the analyzing to align the channel and lens optic axes based on the analyzing. ,Method.

100 inspection apparatus 102 scattered light source, light source 104 light 106 parts, ceramic honeycomb body 108 light 110 telecentric lens 112 camera 114 support chuck 116 vertical reference angle, pitch angle, pitch reference angle 118 controller 120 channel wall 122 horizontal reference angle, yaw angle, Yaw standard angle 510 light part 520 dark part 530 dark part 710 defect, crack, crack defect 720 shadow 730 shadow

Claims (5)

An inspection apparatus for inspecting a ceramic honeycomb body,
Light sources that direct light into the channel of the ceramic honeycomb body;
A lens configured to receive at least a portion of the light transmitted through the channels of the ceramic honeycomb body;
Wherein in the channel a plurality of respective angles of the angle of the optical axis is changed stepwise in the lens, an imaging devices that picks up an image of the transmitted said light through said channel;
Average and for receiving the captured image to analyze the plurality of images captured by the plurality of the angle between the optical axis of the channel and the lens; the ceramic supporting lifting chuck honeycomb body you support The optical axis of the channel and the lens is adjusted by adjusting at least one of the support chuck and the lens to maximize an average light intensity among the plurality of images as compared to the light intensity. to determine the angle to be aligned comprises alignment to Turkey controller the optical axis of the channel and the lens apparatus. The controller for each of the plurality of sectors before SL channel, the corresponding sector to the optical axis of the lens, the imaging at a plurality of respective angles of the angle of the optical axis is changed stepwise in the channel and the lens The sector and the lens by determining an angle to be aligned based on the analysis of the captured image and adjusting at least one of the support chuck and the lens based on the determined alignment angle Configured to align with the optical axis of
The apparatus of claim 1, wherein each said sector comprises at least one channel not parallel to another one of said plurality of sectors.   The apparatus according to claim 2, wherein the number of sectors is 2 to 64. A method of inspection of ceramic honeycomb bodies,
Directing light towards a first end of the ceramic honeycomb body, wherein at least a portion of the light is transmitted through a channel of the ceramic honeycomb body;
Through the lens, comprising the steps of imaging the portion of the light, step comprising the step of imaging a plurality of images at a plurality of respective angles varying stepwise the angle of the optical axis of the channel and the lens;
The light of the channel and the lens is compared by comparing the average light intensity of the captured image at each of the plurality of progressively changed angles and maximizing the average light intensity among the plurality of images. Determining an alignment angle at which the axes are aligned ; and
And adjusting at least one of said ceramic honeycomb body and the lens based on the alignment angle the determined, comprising the step of aligning position of said optical axis of said channel and said lens. The step of determining the alignment angle may
Said ceramic honeycomb body comprising a plurality of sectors, each sector comprising at least one channel not parallel to the channels in at least one other sector, analyzing an image for a sector of said ceramic honeycomb body comprising the step,
Aligning the optical axis of the channel and the lens;
Comprising the step of aligning said optical axis of said sector and said lens in which the image is analyzed, the method according to claim 4.

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